@MELGAR posted:Is it possible that the pony-truck and its wheels follow the straight path through the switch because they are too light or don't have enough download? Is there a coil spring between the pony truck and the underside of the locomotive? Would an increase in spring tension help?
MELGAR
I just examined my 119 after reading this thread. The front truck is not built like our larger die-cast engines with a spring and a large slot the whole truck can "swing" within. It is just a solid single point mount, with the only degree of freedom being a pivot on the center. There may be some very minor play in this mount, but nothing like we are used to with larger steamers. I suspect the extremely small wheelbase is what allowed this design.
(not this direct situation, but on a similar note: when initially examining my engines at the store, I was shocked at the minimal swing on the tender trucks, considering the engine is rated for O36. After placing it on a stock piece of O36 curve from the box of track at the dealer, the short wheel base aspect of this occurred to me)
@romiller49 posted:If this is the case what guides the engine. Are you stating this correctly or am I not reading it correctly.
See above. The front truck being constrained by the single pivot point anchored at the body should guide the engine. (well, should - this does not explain the OP question )
@tom21pa posted:Should have flanged both drivers.
Maybe not? See my above ideas on why this may be OK for these models (less the switch issue the OP is having).
-Dave